We're dividing 623623 by 21 
We want to divide 623623 by 21.

Let's proceed to step 1:
The number 21 fits into 6 0 times, leaving a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 21

Moving on to step 2:
When dividing 62 by 21, we get 2 with a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 2.0
The remainder is 20 after subtracting 42 from 62.
Grab the next digit (3) from the dividend, add it to 20, then carry on: 203 / 21

On to step 3:
The number 21 fits into 203 9 times, leaving a remainder of 14.
Record the quotient 9 as the next digit in the result. 
Result so far: 29.0
Subtract 189 from 203 to get 14.
Append the next digit (6) from the dividend to 14 and continue with: 146 / 21

Advancing to step 4:
146 divided by 21 is 6 with a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 296.0
Subtract 126 from 146 to get 20.
Fetch the next digit (2) from the dividend, attach it to 20 and continue: 202 / 21

Advancing to step 5:
21 goes into 202 9 times with a remainder of 13.
Write down 9 as next digit of the result. 
Result so far: 2969.0
If we take 189 away from 202, we end up with 13.
Bring next digit (3) of the dividend behind the 13 and repeat the process: 133 / 21

Let's proceed to step 6:
21 can be fit into 133 6 times, resulting in a remainder of 7.
The number 6 becomes the next digit in our result. 
Result so far: 29696.0
If we take 126 away from 133, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 7:
21 can be fit into 70 3 times, resulting in a remainder of 7.
The next digit of our result is 3. 
Result so far: 29696.3
Subtracting 63 from 70 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 8:
70 divided by 21 is 3 with a remainder of 7.
Write down 3 as next digit of the result. 
Result so far: 29696.33
Subtract 63 from 70 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The quotient of the division is 29696.33, and the remainder is 0.007.